From the archives of the AFIP - Neoplasms of the spinal cord and filum terminale: Radiologic-pathologic correlation

Intramedullary spinal cord neoplasms are rare, accounting for about 4%-10% of all central nervous system tumors. Despite their rarity, these lesions a re important to the radiologist because magnetic resonance (MR) imaging is the preoperative study of choice to narrow the differential diagnosis and g uide surgical resection. On contrast material-enhanced MR images, intramedu llary spinal tumors almost always manifest as expansion of the spinal cord and show enhancement. Syringohydromyelia and cystic lesions are frequently associated with intramedullary tumors. Nontumoral cysts tend to be located at the poles of the tumors and do not enhance on contrast-enhanced MR image s, whereas cysts within the substance of the tumor are considered tumoral c ysts and typically demonstrate peripheral enhancement. Spinal cord ependymo mas are the most common type in adults, and cord astrocytomas are most comm on in children. Both entities constitute up to 70% of all intramedullary ne oplasms. A central location within the spinal cord, presence of a cleavage and intense homogeneous enhancement are imaging features that fa-plane, vor an ependymoma. Intramedullary astrocytomas are usually eccentrically locat ed within the cord, are ill defined, and have patchy enhancement after intr avenous contrast material administration. Even with these characteristics, it may not be possible to differentiate these two entities on the basis of imaging features alone. Cord hemangioblastomas are the third most common ty pe of intramedullary spinal tumor. Gangliogliomas commonly extend over more than eight vertebral segments. Paragangliomas and primitive neuroectoderma l tumors have an affinity for the filum terminale and cauda equina. Other s pinal cord tumors include metastatic disease, which is characterized by pro minent cord edema for the size of the enhancing portion, and primary lympho ma.